Nanoscale Modeling of Drug Delivery

S. C. McGrother and G. Goldbeck-WoodAccelrys, US

Keywords: drug delivery, mesoscale, formulations, quantum mechanics

Abstract:In the area of drug delivery, many levels of modeling have useful applications: from the Quantum Mechanical, where the chemical release of a drug from a pegylated device can be rationalized; through the Classical Atomistic, where force-field driven molecular dynamics can be used to establish solubility and diffusion rates; to the Mesoscale, where atomistic detail is sacrificed in order to study longer length and time scales and consequently elucidate formulation characteristics and release profiles.
Herein, we report recent simulations on pegylated drug molecules and their decomposition characteristics, leading to drug release. These simulations use the DMol3 program with numerical basis sets to determine the stable reactants and products of a chemical reaction and use the new LST/QST method to locate transition states and energy barriers for chemical reactions. We mention previously reported results on the use of classical MD to obtain solubility and diffusion rates and ties these in with mesoscale simulations using dissipative particle dynamics and MesoDyn. These simulations show the evolution and composition of complex drug delivery formulations. With changes in external conditions the release of the drug from these devices is seen. Finally we will present the latest trends and future direction of this work.